Intel SL3QA - Pentium III 550 MHz Processor Specification page 76

Workaround: To prevent the risk of power-on boot failures or catastrophic thermal failures, a
platform workaround is required. The system must provide a rising edge on the TCK
signal during the power-on sequence that meets all of the following requirements:
• Rising edge occurs after Vcc_core is valid and stable
• Rising edge occurs before or at the de-assertion of RESET#
• Rising edge occurs after all Vref input signals are at valid voltage levels
• TCK input meets the Vih min and max spec as mentioned in EMTS
Specific workaround implementations may be platform specific.
examples have been tested as acceptable workaround implementations.
In addition, the example workaround circuits shown do not support production
baseboard test methodologies that require the use of the processor JTAG/TAP port.
Alternative workaround solutions must be found if such test capability is required.
Pentium® III Processor with 512KB L2 Cache Platforms Workaround
2.5V
R1
76
330 ohm
R2 R4
150 ohm 0 ohm
R3 680 ohm
PWRGD
CPU1
TCK
TCK
CPU2
PWRGD
Errata
The following
Assumes the inputs
to the CPU_PWRGD
are open collector
signals that are
Wire-ANDed
together
Specification Update